[PATCH v4 1/4] KVM: Recover IRTE to remapped mode if the interrupt is not single-destination

[Feng Wu]

When the interrupt is not single destination any more, we need
to change back IRTE to remapped mode explicitly.

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
---
v4:
- Don't need to Set SN before changing back to remapped mode

 arch/x86/kvm/vmx.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e2951b6..a4b4aa4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10764,8 +10764,21 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
 		 */
 
 		kvm_set_msi_irq(e, &irq);
-		if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu))
+		if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu)) {
+			/*
+			 * Make sure the IRTE is in remapped mode if
+			 * we don't handle it in posted mode.
+			 */
+			ret = irq_set_vcpu_affinity(host_irq, NULL);
+			if (ret < 0) {
+				printk(KERN_INFO
+				   "failed to back to remapped mode, irq: %u\n",
+				   host_irq);
+				goto out;
+			}
+
 			continue;
+		}
 
 		vcpu_info.pi_desc_addr = __pa(vcpu_to_pi_desc(vcpu));
 		vcpu_info.vector = irq.vector;
-- 
2.1.0